1. Field of the Invention
This invention relates to a portable electronic system, and more particularly to a portable electronic system equipped with a spare battery device.
2. Description of the Related Art
The rapid development of digital electronic products makes people's life more convenient. And a lot of portable devices, such as mobile phones, notebooks, or Personal Digital Assistance (PDA), and so on, have been developed rapidly. It highly promotes the convenience of people's life and the efficiency of work. Portable devices, in the circumstance without an external power source, totally rely on batteries to supply the necessary operating power. It is, therefore, very important for the portable devices to have a stable power source supplied.
When a battery has been used for a certain period of time, the battery will not be able to stably supply necessary power to a portable device. Therefore, it is necessary to provide a new battery as a new power source of the portable device.
Besides, it is necessary for a spare battery to have a power-leakage-protection appliance to avoid power leakage when the spare battery is in an idle status. In the present time, a switch is used to be the power-leakage-protection appliance to achieve the goal. That is, a switch is installed into a battery. When the battery is in an idle status, the switch is turned off manually to disable the battery from supplying power. When the battery is needed, the switch is turned on manually to enable the battery for supplying power.
There are some disadvantages using the switch as the power-leakage-protection appliance, which are: (1) the cost of manufacturing and the volume of the portable device increase because a switch is needed; (2) a user may forget to turn off an idle battery due to the manual operation of changing the statuses of the switch. If, at this moment, the positive and negative electrodes of that battery are incidentally conducted, for example, there is just a conductor conducting the positive and negative electrodes, the power of the battery will start to leak out.